At such low velocities what difference does it make? You can run a solid WC per weight same as any style of cast boolit. You can’t with most HBWCs. Depending on alloy how skirt will hold up. The accuracy of loads will be the individual gun as with anything else. I load WCs exclusively in my S&Ws. 38sp- 44sp- 45AR & 45 Colt. I pour my own and favor button nose. I don’t have much experience with my own HBWCs. haven’t had chance to shoot many. Have shot a lot of Hornady 38 HBWCs with outstanding results. Have bought HBWC 44 not used yet.
The only thing I disagree with in above posts is physical mass doesn’t mean equal volume. A solid cylinder is a pretty economical package for weight. If you want to get technical anything extra to cylinder will increase its surface area.